Migration Generator: Default value for JSON column generates a migration for equal values

[cebe]

Schema in OpenAPI:

  customFields:
    type: array
    x-db-type: json
    default: '[]'
    items:
      type: object

generated migration:

class m200803_210001_change_table_projects extends \yii\db\Migration
{
    public function safeUp()
    {
        $this->alterColumn('{{%projects}}', 'customFields', "SET DEFAULT '[]'");
    }

    public function safeDown()
    {
        $this->alterColumn('{{%projects}}', 'customFields', "SET DEFAULT '[]'");
    }
}

There is no change in up and down.

This happens on PostgreSQL